Files
filestash/client/worker/sw_cache.js

131 lines
3.8 KiB
JavaScript

const CACHE_NAME = "v0.3";
/*
* Control everything going through the wire, applying different
* strategy for caching, fetching resources
*/
self.addEventListener("fetch", function(event) {
const errResponse = (err) => (new Response(JSON.stringify({
code: "CANNOT_LOAD",
message: err.message,
}), { status: 502 }));
if (is_a_ressource(event.request)) {
return event.respondWith(cacheFirstStrategy(event).catch(errResponse));
} else if (is_an_api_call(event.request)) {
return event;
} else if (is_an_index(event.request)) {
return event.respondWith(cacheFirstStrategy(event).catch(errResponse));
} else {
return event;
}
});
/*
* When a new service worker is coming in, we need to do a bit of
* cleanup to get rid of the rotten cache
*/
self.addEventListener("activate", function(event) {
vacuum(event);
});
self.addEventListener("error", function(err) {
console.error(err);
});
/*
* When a newly installed service worker is coming in, we want to use it
* straight away (make it active). By default it would be in a "waiting state"
*/
self.addEventListener("install", function() {
caches.open(CACHE_NAME).then(function(cache) {
return cache.addAll([
"/",
"/api/config",
]);
});
if (self.skipWaiting) {
self.skipWaiting();
}
});
function is_a_ressource(request) {
const p = _pathname(request);
if (["assets", "manifest.json", "favicon.ico"].indexOf(p[0]) !== -1) {
return true;
} else if (p[0] === "api" && (p[1] === "config")) {
return true;
}
return false;
}
function is_an_api_call(request) {
return _pathname(request)[0] === "api" ? true : false;
}
function is_an_index(request) {
return ["files", "view", "login", "logout", ""]
.indexOf(_pathname(request)[0]) >= 0? true : false;
}
// //////////////////////////////////////
// HELPERS
// //////////////////////////////////////
function vacuum(event) {
return event.waitUntil(
caches.keys().then(function(cachesName) {
return Promise.all(cachesName.map(function(cacheName) {
if (cacheName !== CACHE_NAME) {
return caches.delete(cacheName);
}
}));
}),
);
}
function _pathname(request) {
return request.url.replace(/^http[s]?:\/\/[^\/]*\//, "").split("/");
}
/*
* strategy is cache first:
* 1. use whatever is in the cache
* 2. perform the network call to update the cache
*/
function cacheFirstStrategy(event) {
return caches.open(CACHE_NAME).then(function(cache) {
return cache.match(event.request).then(function(response) {
if (!response) {
return fetchAndCache(event);
}
fetchAndCache(event).catch(nil);
return response;
});
});
function fetchAndCache(event) {
// A request is a stream and can only be consumed once. Since we are consuming this
// once by cache and once by the browser for fetch, we need to clone the response as
// seen on:
// https://developers.google.com/web/fundamentals/getting-started/primers/service-workers
return fetch(event.request)
.then(function(response) {
if (!response || response.status !== 200) {
return response;
}
// A response is a stream and can only because we want the browser to consume the
// response as well as the cache consuming the response, we need to clone it
const responseClone = response.clone();
caches.open(CACHE_NAME).then(function(cache) {
cache.put(event.request, responseClone);
});
return response;
});
}
function nil() {}
}